Airlines reported 96 tarmac delays of more than three hours on domestic flights in December 2017 compared with no such tarmac delays reported in November, DOT said.

Of the 96 domestic flights with tarmac times of more than three hours, 77 were arriving flights waiting on the Atlanta tarmac during a Dec. 17 power outage. An additional 14 flights were delayed on the tarmac departing Atlanta during a Dec. 8 snowstorm. Four other flights were delayed on the Dallas Fort Worth International tarmac during a Dec. 31 snow and ice storm, according to DOT.

In December, airlines also reported 21 tarmac delays of more than four hours on international flights, compared with no such tarmac delays reported in November. All but two delays were related to the Dec. 17 power outage at Atlanta, DOT said. All reported extended tarmac delays are investigated by the department.